Manufacture of carbon-black and other solid reaction products



w. D. BANCROFT MANUFACTURE OF CARBON BLACK AND OTHER SOLID REACTION PRODUCTS.

APPLICATW H HLED JAN- 3| 1920- PatentedSept. 13,1921;

WEBER, I). BAfilCRDFT/OF I'JZHACA, NEVL YORK.

hi'ANUI-ACTURE OF CARBON-BLACK AND SOLID REACTION PRODUCTS.

rescues.

Specification of I ietters Patent; -Pe=fniifll Sept. 13, 1921.

Application filed January 3, 1920. Serial Ho. 29,138.

To all mm. it may concern:

Be it known that I, Vmonn D. BANCRQFT, a citizen of the United States, residing at Ithaca, in the county of Ton1phins and State of lie-w lurk, have invented certain nee and useful Improvements in the Menu lecture of Carbon-Block and other Solid leection Products, of which the following is e specification.

cable to the conductof certain high-temperature reactions in the course of which a gas or gas-mixture{including 'opors or "vapormixtures) yields a finely divided, solid reecrying out this-or similar gas reactions yield mg a solid reaction productinie seats of minute division, I establish inproximity to the reaction zone, which is usually hounded by a, inetellicor other surface, a tempereture-gredient having for its purpose end eilectv the rapid remov'alof the solid reaction product, or a substantial proportion thereof, from the region of maximum temperature to 21 point out-side the zone of reaction.

lt-is known that; dust particles suspended in air and introduced between very closely spaced parallel surfaces maintained at ditfering temperatures, tend to move toward and to deposit upon the cooler surface. (Aih ken Transactions B 07 01 'Socic 151 Edinburgh. Vol. 32, p. 239, 1884 On the Format-ion of Small Clear Spaces in, Dusty Air However, so for as I am aware, no industrial use has ever been made or proposed to be made of this tendency ofsolid purticlesto move along a heat-gradient. 'lemploy this printicles from a reaction zone, in those cases Where the prolonged action of heat would he in urious t the iu'crluct or detrimental to-the cilieieucy oi the reaction.

Carbon black is now commonly made by burning natural gas with e proportion of air iz1suiiic'.u1t for complete con'rhustioii, and causing the flame to impinge on a. cold sur- Ziocc. The quality of the carbon hlscl: thus produced is good hue the yield is only about 1% of the carbon content of i-he Yields up to 10% ere said to have been obtoined by cracking natural gas in contac: with a highly heated surface such as pumice, hutithe quelitv of the product so produced is'poor. I believe that the inferior quality of this product. is due to the foot that. the conditions of operation necessitate its remeining for considerable periods in the heatzone. This invention is a novel process appliln contraclistinctionto the foregoing, I creel: the gas at a heated surface; but under such conditions that eniaterial proportion at least of the resulting carbon is immedistely and positively transferred to e relatlvely cool surface. Thereby I obtain im proved yields, and also a product of satief'actory quality; results Which'cunnot be coincidently secured by either of the known processes mentioned above.

As as means for eliecting the reniorol of the carbon particles fromsthe heated, zone,

I establish 9. sutlicient heat-gradient from the hot cracking surface toe relatively cool collecting surface. I prefer a temperature gradient of the order of C. {561' centimeter, although my invention is notlimited thereto.

lily invention not rescrictetl to the use of any particular type of apparatus. Suitable apparatus may comprise siinply opposed parallel plane or curved surfaces, disposed in the reaction chamber, arranged at any desired angle, and provided with means for maintaining them at Widely differing temperatures, the higher temperature op- ".proximeting the optimum for the particular reaction in question. For example in the plarticuler case chosen for illustration the cracking surface nmy he of copper or other refractory metal or alloy, heated in any suitable manner asior instance by a. flame from ciple to effect the rapid removal of solid parof steam or other addition serving in any way to {militate the reaction or to assist the operation is within the scope of my invent Y ie opposing or collecting surface is tereoly water-or sloeun coolecl. A temper.tore-gradient; mentioned, shore, of

shout LOO ill. per centimeter, would in this order of 10 centimeters.

case be obtained with an inter-space of the Preferably the highly heated surface will be disposed above the cooler'surface, in order to take advantage of the effects of gravitation upon the solid particles as Well as upon the heated gas. Any suitable mechanical means may be provided for the continuous or intermittent discharge of the collected solid, such for example as scrapers, the provision of a moving water-cooled conveyor as a collectinvention that it tends to keep the cracking surface free from a deposit of carbon, and thus to permit the effective use of desirable catalysts, including copper, nickel, nickel alloys and car-bids, &c.

A simple formcf apparatus illustrative of the invention is diagrammatically shown in the accompanying drawing in which the figure is a central vertical section In said figure the heated or cracking surface is represented at 1, and the cooled or collecting surface at 2, the temperature gradient being maintained between these surfaces as already described. The hydrocarbon gas is distributed between the surfaces, as by a perforated pipe 3. The cooled surface 2 in the illutsration takes the form of a wateror steanncooled drum, having a slow movement combustion, into the combustion chamber 7,

surmounting the cracking plate 1,. The pro ducts of combustion escape at 8.

It is within the scope of my invention to assist and accelerate the transfer of the solid reaction product to the collecting surface by known means, including the use of an electric discharge as in the known electrical precipitation processes. I p

I claim 2- v 1i Process of removing a finely divided reaction product from a reaction zone, -comprising maintaining in proximity to said reaction zone a temperaturegradlent sufficient to effect a transfer of a material proportion of the solid product to a cooler zone, and collecting said solid product.

2. Process of making carbon black, comprising cracking a gaseous hydrocarbon in contact with a highly heated surface, and

maintaining in proximity to said surface a temperature-gradient sufiicient to effect a transfer of a material proportion of the carbon to a cooler zone.

3. Process according to claim 2 in which the temperaturegradient is of. the order of 100 C. per centimeter.

In testimony whereof, I affix my signature.

\VILDER D. BANCROFT. 

